[Bug c++/71350] New: internal compiler error on trailing return type declaration with initializer list

["joostvanzwieten at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71350

            Bug ID: 71350
           Summary: internal compiler error on trailing return type
                    declaration with initializer list
           Product: gcc
           Version: 4.9.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: joostvanzwieten at gmail dot com
  Target Milestone: ---

Created attachment 38601
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38601&action=edit
minimal example producing the internal compiler error

A student of mine stumbled upon an internal compiler error related to a
trailing return type declaration containing an initializer list. I've attached
a minimal example producing the error with Debian's versions 4.9.3-14,
5.3.1-21, 6.1.1-4 and 7.0 (revision 236009, package gcc-snapshot), all from
Debian Sid, with the flag `-std=c++11`. Note that the example should not
compile due to the incorrect return value in method `Foo::bar`.

The output of `g++-6 -v -std=c++11 -save-temps bug.cc` follows.

Best, Joost


Using built-in specs.
COLLECT_GCC=g++-6
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/6/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 6.1.1-4'
--with-bugurl=file:///usr/share/doc/gcc-6/README.Bugs
--enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-6 --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-libmpx --enable-plugin --with-system-zlib
--disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-6-amd64/jre --enable-java-home
--with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-6-amd64
--with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-6-amd64
--with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar
--enable-objc-gc --enable-multiarch --with-arch-32=i686 --with-abi=m64
--with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 6.1.1 20160519 (Debian 6.1.1-4) 
COLLECT_GCC_OPTIONS='-v' '-std=c++11' '-save-temps' '-shared-libgcc'
'-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/6/cc1plus -E -quiet -v -imultiarch
x86_64-linux-gnu -D_GNU_SOURCE bug.cc -mtune=generic -march=x86-64 -std=c++11
-fpch-preprocess -o bug.ii
ignoring duplicate directory "/usr/include/x86_64-linux-gnu/c++/6"
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-linux-gnu/6/../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/6
 /usr/include/x86_64-linux-gnu/c++/6
 /usr/include/c++/6/backward
 /usr/lib/gcc/x86_64-linux-gnu/6/include
 /usr/local/include
 /usr/lib/gcc/x86_64-linux-gnu/6/include-fixed
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-std=c++11' '-save-temps' '-shared-libgcc'
'-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/6/cc1plus -fpreprocessed bug.ii -quiet -dumpbase
bug.cc -mtune=generic -march=x86-64 -auxbase bug -std=c++11 -version -o bug.s
GNU C++11 (Debian 6.1.1-4) version 6.1.1 20160519 (x86_64-linux-gnu)
        compiled by GNU C version 6.1.1 20160519, GMP version 6.1.0, MPFR
version 3.1.4, MPC version 1.0.3, isl version 0.15
warning: MPFR header version 3.1.4 differs from library version 3.1.4-p2.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C++11 (Debian 6.1.1-4) version 6.1.1 20160519 (x86_64-linux-gnu)
        compiled by GNU C version 6.1.1 20160519, GMP version 6.1.0, MPFR
version 3.1.4, MPC version 1.0.3, isl version 0.15
warning: MPFR header version 3.1.4 differs from library version 3.1.4-p2.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 1edfa0d359b2ee208224c72d1e98c75a
'
Internal compiler error: Error reporting routines re-entered.
0x5e042b reshape_init_r
        ../../src/gcc/cp/decl.c:5896
0x5e0644 reshape_init_class
        ../../src/gcc/cp/decl.c:5673
0x5e0644 reshape_init_r
        ../../src/gcc/cp/decl.c:5901
0x5dfe7d reshape_init(tree_node*, tree_node*, int)
        ../../src/gcc/cp/decl.c:5945
0x5d2a55 implicit_conversion
        ../../src/gcc/cp/call.c:1795
0x5d36db reference_binding
        ../../src/gcc/cp/call.c:1525
0x5d286c implicit_conversion
        ../../src/gcc/cp/call.c:1802
0x5d3f48 add_function_candidate
        ../../src/gcc/cp/call.c:2121
0x5d4bef add_candidates
        ../../src/gcc/cp/call.c:5354
0x5daa6f build_new_op_1
        ../../src/gcc/cp/call.c:5491
0x5daf5e build_new_op(unsigned int, tree_code, int, tree_node*, tree_node*,
tree_node*, tree_node**, int)
        ../../src/gcc/cp/call.c:5827
0x6814f5 build_x_array_ref(unsigned int, tree_node*, tree_node*, int)
        ../../src/gcc/cp/typeck.c:3918
0x60be66 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../src/gcc/cp/pt.c:16210
0x60ce58 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../src/gcc/cp/pt.c:16177
0x60e8d9 tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../src/gcc/cp/pt.c:13527
0x642870 dump_template_bindings
        ../../src/gcc/cp/error.c:349
0x642870 dump_substitution
        ../../src/gcc/cp/error.c:1450
0x6482e4 decl_to_string
        ../../src/gcc/cp/error.c:2955
0x6482e4 cp_printer
        ../../src/gcc/cp/error.c:3535
0x112bfec pp_format(pretty_printer*, text_info*)
        ../../src/gcc/pretty-print.c:631
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <file:///usr/share/doc/gcc-6/README.Bugs> for instructions.